title: Telomerase activation in nasopharyngeal carcinomas.
abstract: Nasopharyngeal carcinomas (NPC) are common in Hong Kong and southern China but rare in Western countries. Telomerase activation is common in human cancers but has not been reported previously in NPC. Telomerase activation in NPC was determined using the sensitive TRAP (telomerase rapid amplification protocol) assay in 45 nasopharyngeal biopsies (36 NPC, nine normal nasopharyngeal mucosae) in four xenografted NPC tumours established in nude mice and in five in vitro NPC cell lines. Telomerase activation is common in NPC and can be detected at high frequencies (85% in primary tumours and 100% in recurrent tumours). The frequency of telomerase activation was lowest in NPC biopsies without lymph node involvement (60%) compared with those with positive lymph node involvement (100%), and the difference is statistically significant (P < 0.05; Fisher exact test). All the xenografted NPC tumours and in vitro NPC cell lines were strongly positive for telomerase activity. Our results suggest that telomerase activation is common in NPC and it may be useful as a diagnostic marker in the detection of tumour cells in nasopharyngeal biopsies. The high frequency of telomerase activation in stage I NPC (80% positive) suggests that it is an early event in tumour progression.
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Hong Kong, Pokfulam.
authors.forename: R Y
authors.initials: RY
authors.lastname: Cheng
authors.forename: P W
authors.initials: PW
authors.lastname: Yuen
authors.forename: J M
authors.initials: JM
authors.lastname: Nicholls
authors.forename: Z
authors.initials: Z
authors.lastname: Zheng
authors.forename: W
authors.initials: W
authors.lastname: Wei
authors.forename: J S
authors.initials: JS
authors.lastname: Sham
authors.forename: X H
authors.initials: XH
authors.lastname: Yang
authors.forename: L
authors.initials: L
authors.lastname: Cao
authors.forename: D P
authors.initials: DP
authors.lastname: Huang
authors.forename: S W
authors.initials: SW
authors.lastname: Tsao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000201:enzymology*; D009368:Neoplasm Transplantation; D016133:Polymerase Chain Reaction; D019098:Telomerase / Q000378:metabolism*; D014183:Transplantation, Heterologous
chemical_list: D019098:Telomerase